/*
 * ------------------------------------------------------------------------
 *  Copyright by KNIME AG, Zurich, Switzerland
 *  Website: http://www.knime.com; Email: contact@knime.com
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License, Version 3, as
 *  published by the Free Software Foundation.
 *
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 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses>.
 *
 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  KNIME interoperates with ECLIPSE solely via ECLIPSE's plug-in APIs.
 *  Hence, KNIME and ECLIPSE are both independent programs and are not
 *  derived from each other. Should, however, the interpretation of the
 *  GNU GPL Version 3 ("License") under any applicable laws result in
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 *  you the additional permission to use and propagate KNIME together with
 *  ECLIPSE with only the license terms in place for ECLIPSE applying to
 *  ECLIPSE and the GNU GPL Version 3 applying for KNIME, provided the
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 *  propagation of ECLIPSE together with KNIME.
 *
 *  Additional permission relating to nodes for KNIME that extend the Node
 *  Extension (and in particular that are based on subclasses of NodeModel,
 *  NodeDialog, and NodeView) and that only interoperate with KNIME through
 *  standard APIs ("Nodes"):
 *  Nodes are deemed to be separate and independent programs and to not be
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 *  License, the License does not apply to Nodes, you are not required to
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 *  may freely choose the license terms applicable to such Node, including
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 * ---------------------------------------------------------------------
 *
 * History
 *   Sep 4, 2009 (morent): created
 */
package org.knime.base.node.mine.decisiontree2;

import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * Contains the set operators that are specified in PMML for
 * SimpleSetPredicates.
 *
 * @author Dominik Morent, KNIME AG, Zurich, Switzerland
 */
public enum PMMLSetOperator {
    /** is missing operator. */
    IS_IN("isIn"),
    /** is not missing operator. */
    IS_NOT_IN("isNotIn");

    private final String m_represent;

    private PMMLSetOperator(final String represent) {
        m_represent = represent;
    }

    private PMMLSetOperator() {
        m_represent = null;
    }

    private static final Map<String, PMMLSetOperator> LOOKUP =
            new HashMap<String, PMMLSetOperator>();

    static {
        for (PMMLSetOperator op : EnumSet.allOf(PMMLSetOperator.class)) {
            LOOKUP.put(op.toString(), op);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        if (m_represent != null) {
            return m_represent;
        }
        return super.toString();
    }

    /**
     * Returns the corresponding operator for the passed representation.
     *
     * @param represent the representation to find the operator for
     * @return the operator
     * @throws InstantiationException - if no such PMML operator exists
     */
    public static PMMLSetOperator get(final String represent)
            throws InstantiationException {
        PMMLSetOperator pmmlSetOperator = LOOKUP.get(represent);
        if (pmmlSetOperator == null) {
            throw new InstantiationException("Illegal PMML set operator type '"
                    + represent);
        }
        return pmmlSetOperator;
    }

    /**
     * Evaluates the operator on the passed value.
     * @param <T> The type of the parameters to be evaluated.
     *
     * @param a the value to check
     * @param set the set to compare against
     * @return the result of the operation
     */
    public <T> boolean evaluate(final T a, final Set<T> set) {
        if (a == null || set == null) {
            return false;
        }
        switch (this) {
            case IS_IN:
                return set.contains(a);
            case IS_NOT_IN:
                return !set.contains(a);
        }
        // we should never arrive here
        assert false;
        return false;
    }

}
